C/Py difference: keys that are the same object

[jamadden]

The C implementation does a comparison by first checking whether the two keys are the same pointer; the Python implementation just goes right to the == operator. In some cases of (broken?) objects this leads to a discrepancy: The C implementation can find a key, but the Python implementation cannot.

I would suggest that the Python implementation should use k is key or k == key to clear this up.

See https://groups.google.com/forum/#!topic/zodb/xhVM0ejl6aE